Stringing means for a badminton racket

ABSTRACT

A stringing means is made integrally with, or an independent device secured on, the throat of a badminton racket. The badminton racket includes a hoop-shaped head with a longitudinal axis, a shaft and a throat connecting the shaft to the head along the longitudinal axis thereof. The head of the racket defines a stringed hitting surface with a sweet zone. The stringing means comprises at least two guiding holes and a guiding channel. Each of the guiding holes is spaced apart in a predetermined distance and includes an opened outer end to be as a string inlet and an inner end connected with the guiding channel. When a badminton racket is equipped with such a stringing means, portions of the string chords for forming the sweet zone of the stringed hitting surface can thread through the means and extend in parallel with the longitudinal axis of the head.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to badminton rackets and particularly to a stringing means for a badminton racket.

2. Description of the Related Art

It is well known that badminton rackets typically include a hoop-shaped head and a shaft downwardly and outwardly extending from the head. The shaft usually includes a handle attached to the proximal end thereof. The handle generally is covered by a grip.

The head of such prior art badminton rackets normally is constructed to have a longitudinal axis, a transverse axis and a set of string holes to be threaded through by tensioned strings to form a stringed hitting surface with a sweet zone. The string holes are usually arranged in two groups. A first or longitudinal group of string holes are disposed on the upper and lower portions of the head and each longitudinal string hole has an axis parallel to the longitudinal axis of the head so that the stringed hitting surface includes a plurality of longitudinal string chords which thread through the longitudinal string holes and extend in parallel with the longitudinal axis of the head. A second or transverse group of string holes are disposed on the right and left portions of the head and each transverse string hole has an axis parallel to the transverse axis of the head to construct a plurality of transverse string chords extending in parallel with the transverse axis of the head. The head usually connects with the shaft at a single region as opposed to two or more areas commonly used with tennis racquets. This single connection region is hereinafter referred to as throat.

For being a joint of the head and the shaft, the throat is formed as an area that stress concentrates. In other words, when the badminton racket impacts a shuttlecock, the head and shaft will place a large amount of stress on the throat. As a result, it is not uncommon for badminton rackets to prematurely fail at the throat.

To address the premature failure issue, some existing badminton rackets have included T-shaped joints at the throat thereof. However, actually, there remained some problems yet to be solved. For example, the throat including T-shaped joint inherently required to be constructed with larger dimensions than the other racket portions. As a result, the axes of the longitudinal string holes disposed near the throat cannot parallel to the longitudinal axis of the head of the badminton racket, as shown in FIG. 3( a) of U.S. Pat. No. 4,575,084, so that the string chords passing through such string holes tiltedly extend as comparing with other longitudinal string chords. This means that the friction between the inner wall of the longitudinal string holes and the string chords passing therethrough will be increased. Because the string chords near the throat construct the sweet zone of the stringed hitting surface, the rather large friction can negatively effect the tension transmitting of the string chords of the sweet zone, as a result, the playability of the racket is also negatively affected.

Thus, there is a need for a badminton racket that inhibits premature failure at the throat thereof without negatively affecting the tension transmitting of the strings chords of the sweet zone. Further speaking, what is needed is an improved stringing design that can effectively reduce the friction between the strings chords of the sweet zone and the inner wall of the string holes through which the string chords of the sweet zone thread.

SUMMARY OF THE INVENTION

The present invention provides a stringing means for a badminton racket wherein the racket includes a hoop-shaped head with a longitudinal axis, a shaft and a throat connecting the shaft to the head along the longitudinal axis thereof. The head of the racket defines a stringed hitting surface with a sweet zone. The stringing means is disposed on the throat of the racket and constructed in such a way that portions of the string chords for forming the sweet zone of the stringed hitting surface can thread through the means and extend in parallel with the longitudinal axis of the head.

According to a principal aspect of the present invention, a badminton racket comprises a hoop-shaped head with a longitudinal axis, a shaft and a throat connecting the head and the shaft along the longitudinal axis of the head. The head has an inner surface, an outer surfaces and a plurality of string holes disposed between the inner and outer surfaces to be threaded through by a tensioned string to form a stringed hitting surface with a sweet zone. The racket further comprises a stringing means disposed on the throat and constructed in such a way that portions of string chords for forming the sweet zone of the stringed hitting surface can thread through the means and extend in parallel with the longitudinal axis of the head.

According to another principal aspect of the present invention, a stringing means is integrally formed with the throat of a badminton racket. The stringing means comprises at least two guiding holes spaced apart in a predetermined distance and a guiding channel. Each of the guiding holes includes an opened outer end to be as a string inlet, and an inner end connected with the guiding channel.

According to a further principal aspect of the present invention, a stringing means comprises a body provided for being mounted on the throat of the badminton racket. The means further comprises at least two guiding holes and a guiding channel. The guiding holes are disposed on the body and spaced apart in a predetermined distance. Each of the guiding holes includes an opened outer end to be as a string inlet and an inner end. The guiding channel is also disposed on the body and connected with the inner end of each of the guiding holes. Thus, when the body is mounted on the throat of the badminton racket, portions of the string chords of the sweet zone of the stringed hitting surface will string through the body and extend in parallel with the longitudinal axis of the head of the racket.

The present invention will become more fully understood from the following detailed description, taken in conjunction with the drawings accompanying the application.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front perspective view of a badminton racket with a stringing means according to a first preferred embodiment of the present invention;

FIG. 2 is a merged drawing combined with an enlarged view of the upper portion of the head of the badminton racket of FIG. 1 and a cross-sectional view of the throat of the badminton racket of FIG. 1 taken along line 2-2 of FIG. 1;

FIG. 3 is a cross-sectional view of the throat of a badminton racket with a stringing means in accordance with a second preferred embodiment of the present invention;

FIG. 4 is an enlarged view of the throat of a badminton racket on which a stringing means in accordance with a third preferred embodiment of the present invention is secured;

FIG. 5 is a perspective view of the stringing means shown in FIG. 4; and

FIG. 6 is a cross-sectional view taken along line 6-6 of FIG. 4.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring firstly to FIG. 1, a badminton racket is indicated generally at 10. Racket 10 includes a hoop-shaped head 12, a shaft 14 and a handle 16.

Hoop-shaped head 12 has a longitudinal axis X-X′, a transverse axis Y-Y′, an inner surface 122 and an outer surfaces 124. Shaft 14 extends along axis X-X′ and has a proximate end connected to the bottom portion of head 12 by a throat 24. Connected to a distal end of shaft 14 is handle 16. In this embodiment, head 12, throat 24 and shaft 14 is made integrally of lightweight materials, such as aluminum alloy, FRP etc. Therefore, the upper surface 242 of throat 24 is also a portion of inner surface 122 of head 12.

Disposed between inner and outer surfaces 122, 124 are a plurality of transverse string holes 18 and a plurality of longitudinal string holes 20. A string 100 tensionedly threads through string holes 18, 20 to form a stringed hitting surface 22 with a sweet zone 222.

Badminton racket 10 further comprises a stringing means 30 disposed on throat 24. In this embodiment, stringing means 30 integrally formed with throat 24 and includes two guiding holes 32, 34 spaced apart in a predetermined distance and a guiding channel 36 with a curved bearing surface 362. Each of guiding holes 32, 34 has an opened outer end 322, 324 to be as a string inlet and an inner end connected with guiding channel 36. Speaking detailedly, each of guiding holes 32, 34 corresponds respectively to one of top string holes 201, 202 disposed on the upper portion of head 12. The distance D between guiding holes 32, 34 is equal to the distance D′ between top string holes 201, 202 so that guiding hole 32 and top string hole 201 have a first common axis and guiding hole 34 and top string hole 202 have a second common axis. Thus, string 100 coming from top string hole 201 will extend in parallel with longitudinal axis X-X′ of head 12, then enter into guiding hole 32 from opened end 322, form a loop 102 received on curved bearing surface 362, pass out from opened end 324 of guiding hole 34, extend in parallel with longitudinal axis X-X′ of head 12 and lastly thread through top string hole 202.

As shown in FIG. 2, for having stringing means 20 disposed on throat 24, the two major longitudinal string chords of sweet zone 222 of stringed hitting surface 22 extend in parallel with longitudinal axis X-X′ of head 12 rather than extend at an angle therewith. The result is that the friction between each of the two major longitudinal string chords of sweet zone 222 and the inner wall of each of the string holes through which the major longitudinal string chord of sweet zone 222 threads is effectively reduced. Thus, the objects or advantages of the present invention can be achieved.

Referring to FIG. 3, in a particularly preferred embodiment, a stringing means 40 is also formed integrally with the throat of a badminton racket. Stringing means 40 is substantially the same as stringing means 30 described above. The difference between stringing means 40 and stringing means 30 is that curved bearing surface 422 of guiding channel 42 of stringing means 40 has a pair of suspending portion 424, 426 disposed respectively on opposing longitudinal ends thereof. In this embodiment, each of suspending portions 424, 426 is a projecting area facing to guiding holes 44, 46. This ensures that string threads through guiding channel 42 without touching the inner wall of each of guiding holes 44, 46 and means the friction between the inner wall of guiding holes 44, 46 and the string threading therethrough will be largely reduced. As a result, the tension among the string chords of the sweet zone produced during impacting a shuttlecock can be smoothly transmitted.

FIGS. 4-6 show a further alternative stringing means 50 embodied according to the present invention. In this embodiment, stringing means 50 is an independent device secured on throat 82 of badminton racket 80. Stringing means 50 includes a block body 51 made of lightweight materials, such as FRP, aluminum, titanium or other metallic alloys. Block body 51 has a top surface 52, a bottom surface 54 and side surface 56, 58.

Stringing means 50 further includes a pair of guiding holes 60, 62 and a guiding channel 64. Guiding holes 60, 62 is disposed on body 51 and spaced apart in a distance “d” and extend from top surface 52 to bottom surface 58. The distance “d” is equal to the distance of a pair of upper string holes (not shown in the drawings) of badminton racket 80 to which guiding holes 60, 62 correspond. Guiding channel 64 is also disposed on body 51 and has a pair of opposing open ends connected respectively with each of guiding holes 60, 62.

As shown in FIG. 4, in this embodiment, stringing means 50 is secured on top surface 822 of throat 82 of badminton racket 80 by two screws 70, 72 screwing into a pair of through holes 66, 68 disposed on body 51. Each of guiding holes 60, 62 preferably has an opened side 602 , 622 so that an U-shaped stringing channel can be formed on body 51 for being easily threaded through.

When badminton racket 80 is constructed to have stringing means 50 secured on throat 82 thereof, as shown in FIG. 6, string 100 coming from top string hole will extend in parallel with longitudinal axis of the head of the racket to enter into guiding hole 60 from opened end 602, then form a loop 102 received on curved bearing surface 642, and then pass out from opened end 622 of guiding hole 62, lastly extend in parallel with longitudinal to the top string hole. Thus, the two major longitudinal string chords located on the sweet zone of the stringed hitting surface of the badminton racket 80 will extend in parallel with the longitudinal axis of the head of the racket 80 rather than extend at an angle therewith. Therefore, the objects or advantages of the present invention are achieved. 

What is claimed is:
 1. A stringing means for a badminton racket wherein the racket includes a hoop-shaped head with a longitudinal axis, a shaft and a throat connecting the shaft to the head along the longitudinal axis thereof, the head defines a stringed hitting surface with a sweet zone, said stringing means is disposed on the throat of the racket and constructed in such a way that portions of the string chords of the sweet zone of the stringed hitting surface can string through said stringing means and extend in parallel with the longitudinal axis of the head of the racket.
 2. The stringing means of claim 1, wherein said stringing means is integrally formed with the throat and comprises at least two guiding holes spaced apart in a predetermined distance and a guiding channel; each of said guiding holes includes an opened outer end to be as a string inlet and an inner end connected with said guiding channel.
 3. The stringing means of claim 2, wherein said guiding channel has a curved bearing surface with opposing longitudinal ends.
 4. The stringing means of claim 3, wherein said guiding channel includes a pair of suspending portions, each of said suspending portions is disposed respectively on each of said longitudinal ends of said curved bearing surface.
 5. The stringing means of claim 4, wherein each of said suspending portions is a projecting area facing to each of said guiding holes.
 6. A badminton racket comprising a hoop-shaped head with a longitudinal axis, a shaft and a throat connecting the shaft to the head along the longitudinal axis thereof, said head having an inner surface, an outer surfaces and a plurality of string holes disposed between said inner and outer surfaces to be threaded through by a tensioned string to form a stringed hitting surface with a sweet zone; said racket further comprising a stringing means disposed on the throat thereof and constructed in such a way that portions of string chords of the sweet zone of the stringed hitting surface can thread therethrough and extend in parallel with the longitudinal axis of the head.
 7. The badminton racket of claim 6, wherein said stringing means is integrally formed with the throat and comprises at least two guiding holes spaced apart in a predetermined distance and a guiding channel, each of said guiding holes includes an opened outer end to be as a string inlet and an inner end connected with said guiding channel.
 8. The badminton racket of claim 7, wherein said guiding channel has a curved bearing surface with opposing longitudinal ends.
 9. The badminton racket of claim 8, wherein said guiding channel further includes a pair of suspending portions, each of said suspending portions is disposed respectively on each of said longitudinal ends of said curved bearing surface.
 10. The badminton racket of claim 9, wherein each of said suspending portions is a projecting area facing to each of said guiding holes.
 11. The badminton racket of claim 7, wherein the string holes includes two upper string holes disposed on the upper portion of the head, each of said upper string holes respectively corresponds to one of said guiding holes such that each of said upper string holes and each of said guiding holes to which said upper string hole corresponds are in a common axis.
 12. The stringing means of claim 1, wherein said stringing means comprises a block body secured on the throat of the badminton racket.
 13. The stringing means of claim 12, further comprising at least two guiding holes and a guiding channel, each of said guiding holes being disposed on said body and spaced apart in a predetermined distance, each of said guiding holes including an opened outer end to be as a string inlet and an inner end, said guiding channel being disposed on said body and connected with said inner end of each of said guiding holes.
 14. The stringing means of claim 13, wherein said guiding channel has a curved bearing surface with opposing longitudinal ends.
 15. The stringing means of claim 14, wherein said guiding channel further includes a pair of suspending portions, each of said suspending portions is disposed respectively on each of said longitudinal ends of said curved bearing surface.
 16. The stringing means of claim 14, wherein each of said suspending portions is a projecting area facing to each of said guiding holes.
 17. The stringing means of claim 12, wherein said body includes through holes to be tightly secured on the throat of the badminton racket by screws or the like.
 18. The stringing means of claim 13, wherein each of said guiding holes has an opened side. 